Water condenser

ABSTRACT

A water condenser includes a fan which draws a primary airflow through an upstream refrigerant evaporator, through an air-to-air heat exchanger and in one embodiment also an air-to-water heat exchanger uses cold water collected as condensate from the evaporator, the airflow to the evaporator being pre-cooled by passing through the air-to-air heat exchanger and the air-to-water heat exchanger prior to entry into the evaporator wherein the airflow is further cooled to below its dew point so as to condense moisture onto the evaporator for gravity collection. The evaporator is cooled by a closed refrigerant circuit. The refrigerant condenser for the closed refrigerant circuit may employ the fan drawing the airflow through the evaporator or a separate fan, both of which drawing an auxiliary airflow separate from the airflow through the evaporator through a manifold whereby both the auxiliary airflow and the airflow through the evaporator, or just the auxiliary airflow are guided through the condenser and corresponding fan.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from U.S. Provisional PatentApplication No. 60/632,077 filed Nov. 16, 2004 entitled Portable PotableWater Condenser.

FIELD OF THE INVENTION

This invention relates to the field of water condensers generally, andin particular to a water condenser providing for optimized controlledcooling of an ambient airflow to its dew point temperature so as tocondense moisture from the ambient air to provide potable water.

BACKGROUND OF THE INVENTION

At any given moment the earth's atmosphere contains 326 million cubicmiles of water and of this, 97% is saltwater and only 3% is fresh water.Of the 3% that is fresh water, 70% is frozen in Antarctica and of theremaining 30% only 0.7% is found in liquid form. Atmospheric aircontains 0.16% of this 0.7% or 4,000 cubic miles of water which is 8times the amount of water found in all the rivers of the world.

0.16% of that 0.7% is found in the atmosphere

0.8% of that 0.7% is found in soil moisture

1.4% of that 0.7% is found in lakes

97.5% of that 0.7% is found in groundwater

Nature maintains this ratio by accelerating or retarding the rates ofevaporation and condensation, irrespective of the activities of man. Itis the sole source and means of regenerating wholesome water for allforms of life on earth.

In addition, most of the world's fresh water sources are contaminated. Atotal of 1.2 billion people in the world lack access to safe drinkingwater and 2.9 billion people do not have access to proper sanitationsystems (World Health Organization). As a result, about 3.4 millionpeople, mostly children, die each year from water-related illnesses.According to the United Nations, 31 countries in the world are currentlyfacing water stress and over one billion people lack access to cleanwater. Half of humanity lacks basic sanitation services and water-bornepathogens kill 25 million people every year. Every 8 seconds, a childdies from drinking contaminated water. Furthermore, unless wedramatically change our ways, by 2025, close to two-thirds of theworld's population will be living with severe freshwater shortages.

There is a huge global need for cost effective and scalable sources ofpotable water. Current technologies require too much energy to operateefficiently and the resultant cost of treated water puts thesetechnologies out-of-reach for the majority in need. Desalination plantsexist in rich nations such as the United States and Saudi Arabia but arenot feasible everywhere. The lack of infrastructure in developingnations makes large plants with high-volume production impractical, asthere is no way to transport the water efficiently.

There is a need for small scalable water extraction plants that willmeet the needs of individuals, communities and industries. Thisinvention can responded to that need by developing an extraction unitthat functions off-the-grid to make clean pure water, anywhere where theneed exists.

The present invention is a device that extracts moisture vapor fromatmospheric air for use as a fresh water source. The device may utilizethe sun as the primary energy source thereby eliminating the need forcostly fuels, hydro or battery power sources. The water collectiondevice of the present invention provides flexibility over prior devices,allowing for productive installations in most regions of the world. Asthe water collection device's preferred power source is solar energy,the amount of available power for the device increases as installationsof the device get closer to the equator where it is hotter year round.

The invention is designed to allow one small water cooler sized unit toprovide cooking and drinking water for a family, simply by harvestingthe water vapor from humid air. Private individuals, industries andcommunities could control their own water supply through the use of thedevice's technology. It is practical for many uses in domestic,commercial or military applications and offers ease of use and cleanwater of a highest quality anywhere, anytime. The modular design ofthese devices allow for increased capacity, simply by adding moremodules.

In addition to domestic use larger units based upon the same basictechnology will be appropriate for many other applications where largerwater supplies are required. The 12 Volt compressor of the coolingsystem may be replaced with a larger 110 Volt compressor withappropriately sized components such as the evaporator and the condenserand the unit will be capable of condensing much larger quantities ofwater when electrical power is more readily available.

The devices solar water condenser technology may be applied to a varietyof uses from residential to recreational and from commercial andagricultural to military and life saving in extreme water deprivedregions of the world.

This invention may be used for obtaining pure drinking water, forcooking purposes or for other household uses such as cleaning orbathing. The system may also be used on boats or in vacation areas, oncamping trips, trekking and places where drinking water delivery systemsare not developed. The unit may be used to produce fresh water forbottling purposes or for larger commercial applications such asrestaurants, offices, schools, hotel lobbies, cruise ships, hospitalsand other public buildings. The system may also be used in playingfields and sports arenas.

Additionally, the technology may be used to augment the supply of waterbeing used to irrigate selected crops using micro or drip irrigationsystems. These systems deliver the right amount of water at the righttime, directly to the roots of plants. As well, the technology may beused to for bottled water production or virtually any other applicationwhere water is needed.

The proposed technology provides an opportunity to end much suffering.The death and misery that flow from unsafe water is overwhelming. Morethan 5,000 children die daily from diseases caused by consuming waterand food contaminated with bacteria, according to a recent studyreleased by UNICEF, the World Health Organization (WHO) and the UNEnvironment Program (UNEP).

Currently, 1.2 billion people have no access to safe drinking water andthat number is increasing steadily with forecasts of a potential 2.3billion or one-third of the earth's population without access to safewater by 2025 (World Health Organization's statistics from WorldCommission on Water for the 21st Century). These at-risk children andtheir families are not restricted to rural areas in undeveloped nations.“Millions of poor urban dwellers have been left without water supply andsanitation in the rapidly growing cities of the developing world. Thepoor are often forced to pay exorbitant prices for untreated water, muchof it deadly,” reports William Cosgrove, director of World Water Vision,Paris. Our device can relieve much of this suffering.

A rapid increase in water demand, particularly for industrial andhousehold use, is being driven by population growth and socioeconomicdevelopment. If this growth trend continues, consumption of water by theindustrial sector will be double by 2025 (WMO).

Urban population growth will increase demand for household water, butpoorly planned water and sanitation services will lead to a breakdown inservices for hundreds of millions of people. Many households will remainunconnected to piped water.

The present invention offers a practical and affordable solution to manyof the world's water supply problems.

It should be noted that while much of the prior art is simply extractingwhat it can from the air based upon a simplistic and uncontrolledprocess, some water will be extracted but with little concern forefficiency. This lack of efficiency can be explained by understandingthe different types of heat that are used in the process of extractingwater from air.

The heat that is used to bring air down to dew point is “specific heat”.The heat used to bring the temperature of air below dew point is “latentheat” and represents a dynamic in the condensation process. The optimalcondensation process uses as little “latent heat” as is possible.

For reference, specific heat means:

-   -   1. The ratio of the amount of heat required to raise the        temperature of a unit mass of a substance by one unit of        temperature to the amount of heat required to raise the        temperature of a similar mass of a reference material, usually        water, by the same amount.    -   2. The amount of heat, measured in calories, required to raise        the temperature of one gram of a substance by one Celsius        degree.

Latent heat means:

The quantity of beat absorbed or released by a substance undergoing achange of state, such as ice changing to water or water to steam, atconstant temperature and pressure. This is also called heat oftransformation.

In the optimal condensation process if too much air is drawn through thesystem the system cannot take enough of the total volume of air to atemperature below dew point and will therefore result in poorperformance from the system.

If not enough air is drawn through the device the air temperature willdrop to below dew point but as there is less air moving through thesystem, there is respectively less water available to be drawn from thatair. There are as well other issues that arise when too little air ismoved through the system such as freezing and wasted energy in theoveruse of “latent” beat.

Therefore there is an optimal quantity of air that will travel throughthe system based upon a number of variables and that optimal quantity ofair will change as the other variables change. It is therefore necessaryto have a system that is monitored and reacts to the changes intemperature and humidity so as to ensure ongoing optimal operation isachieved.

SUMMARY OF THE INVENTION

The water condenser according to the present invention is a device thatmay use various input source energy supplies to create a condensationprocess that extracts potable water from atmospheric air.

In one embodiment the water condenser is portable and the refrigerationcycle may be driven by a 12 Volt compressor that allows for an efficientcondensation process for creating a potable water supply. The inputsource energy for the compressor may be supplied from many sources suchas a wind turbine, batteries, or a photovoltaic panel. Additionally thedesign may be fitted with transformers to accommodate other powersupplies such as 110 Volt or 220 Volt systems when such electrical poweris available, or the device may be sized or scaled up so as toaccommodate such electrical power sources directly. For example, thedevice might use a 110 Volt compressor and simply have the device'sother components scaled-up to accommodate the larger compressor.

Rather than filtering water with conventional systems such as reverseosmosis or carbon filtration, the device filters the atmospheric airthen provides a condensation process that lowers the temperature of thatair to below dew point of the airflow. The air is then exposed to anadequate sized, cooled surface area upon which to condense, and thewater is harvested as gravity pulls the water into a storagecompartment.

The disclosed invention creates a high quality water supply through aprocess of filtering air rather than water. The device may be fittedwith a screen to keep out larger contaminates. Downstream of the screenmay be a pre-filter. The pre-filter may be removable for cleaning.Downstream of the pre-filter may be a high quality filter such as a HEPAfilter to ensure the airflow is pure and depleted of contaminates thatmight impede upon the quality of water that is created by thecondensation process downstream of the air filtration.

Rather than using a capillary tube metering mechanism for feedingrefrigerant fluid into the refrigerant evaporator, such as is normallyused for smaller refrigeration systems, the device according to thepresent invention may be fitted with an automatic suction valve so as toallow for the device to adapt to varying loads created by differentenvironments. One object is that the condensation process is to provideefficient processing of atmospheric, that is ambient air. Thus theintake airflow downstream of the air filtration may be pre-cooled, priorto entering a refrigerant evaporator used to condense moisture out ofthe intake airflow, by passing the intake airflow through an air-to-airbeat exchanger, itself cooled by cooled air leaving the evaporator. Thatis, the incoming airflow is cooled before it enters the refrigerantevaporator section by passing it in close proximity in the heatexchanger to the cooled air that is leaving the refrigerant evaporator.Air-to-air heat exchangers may be constructed to be very efficient,reaching 80% efficiency and therefore reducing the temperature of theincoming airflow towards the dew point of the airflow prior to enteringthe refrigerant evaporator reduces the temperature differential ortemperature drop that must obtained by passing the air over cooledsurfaces in the refrigerant evaporator to obtain the dew pointtemperature, and thus may have a significant impact upon the efficiencyof the condensation process and thus the efficiency of the device. Forexample the device may thus be optimized to increase the airflow rateand still be able to reduce the airflow temperature to the dew point, orwill be able to handle very hot inflow temperatures and still reduce thedew point temperature a reasonable airflow volume over time so as toharvest a useful amount of moisture. Sensors provide temperature, forexample ambient, inlet temperatures, refrigerant evaporator inlet andrefrigerant evaporator outlet temperatures, humidity, and fan speed orother air flow rate indicators to the processor to optimize and balancethose variables to maximize harvested moisture volume. Embodiments ofthe present invention may thus include varying the flow of air throughthe system such that the device has a prescribed amount of air passingthrough the refrigerant evaporator and a different flow of air passingthrough the refrigerant condenser of the corresponding refrigerantcircuit, allowing for optimized function.

In addition to the benefits described above our water condenser unit mayadd additional value in further processing. The harvested water may befurther processed so as to increase the value of the water, for exampleby adding back inorganic minerals missing or only present in smallamounts in the water so as to accommodate the perceived value of theseminerals to the consumer. The process may also add organic minerals backinto the water which are of benefit to the human body, rather thansimply adding back inorganic minerals that the human body may not beable to properly assimilate.

There are numerous means by which to put back minerals and traceelements into the harvested water. For example, a small compartment witha hinged door allowing it to be easily accessed may be provided betweena drip plate at the bottom of the refrigerant evaporator and adownstream water storage container so as to have all harvested waterpass through this chamber. A provided mineral puck may inserted intothis chamber by a user so that as harvested water drips over the mineralpuck the puck dissolves thereby adding desired elements to the harvestedwater. The user thereby controls re-mineralization of the harvestedwater. Additional health remedies may also be added to the harvestedwater such as colloidal silver, water oxygenation additives, negativelyionized hydrogen ions or other health enhancing products.

In summary, the water condenser according to the present invention maybe characterized in one aspect as including at least two cooling stagesor first cooling a primary or first air flow flowing through theupstream or first stage of the two stages using an air-to-air heatexchanger, and feeding the primary airflow once cooled in the heatexchanger of one first stage in a refrigerant evaporator wherein theprimary airflow is further cooled in the refrigerant evaporator to itsdew point so as to condense moisture in the primary airflow onto cooledsurfaces of the refrigerant evaporator, whereupon the primary airflow,upon exiting the refrigerant evaporator of the second stage, enters theair-to-air heat exchanger of the first stage to cool the incomingprimary airflow, thereby reducing the temperature differential betweenthe temperature of the incoming primary airflow entering the first stageand the dew point temperature of the primary airflow in the secondstage. A secondary or auxiliary airflow, which in one embodiment may bemixed or joined (collectively referred to herein as being mixed) withthe primary airflow, downstream of the first and second stages so as toincrease the volume of airflow entering a refrigerant condenser in therefrigerant circuit corresponding to the refrigerant evaporator of thesecond stage. Thus if the primary or first airflow has a correspondingfirst mass flow rate, and the secondary or auxiliary airflow has acorresponding second mass flow rate, then the mass flow rate of thecombined airflow entering the refrigerant condenser is the sum of thefirst and second mass flow rates, that is greater than the first massflow rate in the two cooling stages. The two cooling stages may becontained in one or separate housings so long as the primary airflow isin fluid communication between the two stages. One housing includes afirst air intake for entry of the primary airflow. The first air intakeis mounted to the air-to-air heat exchanger.

The air-to-air heat exchanger has a pre-refrigeration set of airconduits cooperating at their upstream end in fluid communication withthe first air intake. The first air intake thus provides for intake ofthe primary airflow into the pre-refrigeration set of air conduits. Theair-to-air heat exchanger also has a post-refrigeration set of conduitsarranged relative to the pre-refrigeration set of air conduits for heattransfer between the pre-refrigeration set of air conduits and thepost-refrigeration set of air conduits.

A first refrigeration or cooling unit (hereinafter collectively arefrigeration unit) such as the refrigerant evaporator cooperates withthe pre-refrigeration set of air conduits for passage of the primaryairflow from a downstream end of the pre-refrigeration set of conduitsinto an upstream end of the first refrigeration unit. The firstrefrigeration unit includes first refrigerated or cooled (hereincollectively or alternatively referred to as refrigerated) surfaces, forexample one or more cooled plates, over which the primary airflow passesas it flows from the upstream end of the first refrigeration unit to thedownstream end of the first refrigeration unit.

The already pre-cooled primary airflow is further cooled in the firstrefrigeration unit below a dew point of the primary airflow so as tocommence condensation of moisture in the primary airflow onto therefrigerated surfaces for gravity-assisted collection of the moistureinto a moisture collector, for example a drip late or pan mounted underor in a lower part of the housing. The downstream end of the firstrefrigeration unit cooperates with, for passage of the primary airflowinto, an upstream end of the post-refrigeration set of air conduits, forexample to then enter the air-to-air heat exchanger so as to pre-coolthe primary airflow before the primary airflow engages the firstrefrigeration unit. Because of pre-cooling by the heat exchanger,condensate may be collected with minimal power requirements. A secondair-to-air heat exchanger may further increase system performance.Collectively the pre-refrigeration and post-refrigeration sets of airconduits form the first cooling stage, and collectively the plate orplates of the refrigerant evaporator form the second cooling stage.

An air-to-water heat exchanger may be provided cooperating with theair-to-air heat exchanger for cooling the primary airflow wherein theprimary airflow is passed through the air-to-water heat exchanger andthe cold moisture from the moisture collector is simultaneously passedthrough the air-to-water heat exchanger so that the moisture cools thefirst airflow. The air-to-water heat exchanger may be either upstream ordownstream of the air-to-air heat exchanger along the primary airflow.

In one embodiment a manifold or air plenum having opposite upstream anddownstream ends cooperates in fluid communication with the downstreamend of the post-refrigeration set of conduits. That is, the upstream endof the air plenum cooperates with the downstream end of thepost-refrigeration set of conduits so that the primary airflow flowsinto the air plenum at the upstream end of the plenum. The plenum has asecondary or auxiliary air intake into the plenum for mixing of theauxiliary airflow with, or addition of the auxiliary airflow in parallelto, the primary airflow in the plenum so as to provide the combined massflow rate into the refrigerant condenser, to extract heat from therefrigerant in the refrigerant circuit to re-condense the refrigerantfor delivery under pressure to the refrigerant evaporator in the secondcooling stage, the refrigerant pressurized between the refrigerantevaporator and condenser by a refrigerant compressor (herein referred toas the compressor). Thus the downstream end of the plenum cooperates influid communication with the refrigerant condenser. An airflow primermover such as a fan or blower (herein collectively a fan) urges theprimary airflow through the two cooling stages. In embodiments whereinboth the primary and auxiliary airflows are directed into therefrigerant condenser (herein also referred to as the combined airflowembodiment), a single airflow prime mover, such as a fan on therefrigerant condenser may be employed, otherwise, where only theauxiliary airflow flows through the refrigerant condenser, separateairflow prime movers are provided for the primary and auxiliaryairflows.

In the combined airflow embodiment, a selectively actuable airflowmetering valve such as a selectively actuable damper may be mounted incooperation with the auxiliary air intake for selectively controllingthe volume and flow rate of the auxiliary airflow passing into theplenum. An automated actuator may cooperate with the metering valve forautomated actuation of the metering valve between open and closedpositions of the valve according to at least one environmental conditionindicative of at least moisture content in the primary and/or auxiliaryairflows (herein “and/or” collectively referred to by the boleanoperator “or”). For example, the automated actuator may be a temperaturesensitive bi-metal actuator or an actuator controlled by a programmablelogic controller (PLC); for example the automated actuator may include aprocessor cooperating with at least one sensor, the at least one sensorfor sensing the at least one environmental condition and communicatingenvironmental data corresponding to the at least one environmentalcondition from the at least one sensor to the processor or PLC. The atleast one environmental condition may be chosen from the groupconsisting of air temperature, humidity, barometric air pressure, airdensity, air mass flow rate. The air temperature conditioner may includethe temperature of the ambient air at the primary airflow intake, andthe temperature of the primary airflows entering and leaving the secondcooling stage.

The processor regulates the first and/or second airflows, for exampleregulates the amount of cooling in the refrigeration unit, so that theair temperature in the first refrigeration unit is at or below the dewpoint of the primary airflow, but above freezing. The processor maycalculate the dew point for the primary airflow based on the at leastone environmental condition sensed by the at least one sensor.

The airflow prime mover may be selectively controllable and theprocessor may regulate the primary, auxiliary or combined airflow so asto minimize the air temperature of the primary airflow from dropping toofar below the dew point for the primary airflow to minimize condensationwithin the heat exchanger, and so as to optimize or maximize the volumeof moisture condensation in the refrigeration unit.

At least one filter may be mounted in cooperation with the watercondenser housing. For example, at least one air filter such as a HEPAfilter may be mounted in the flow path of the first airflow. A waterfilter may be provided for filtering water in the moisture collector.The air filters may include an ultra-violet radiation lamp mounted inproximity to, so as to cooperate with, the primary airflow path or themoisture collector. For example the air filter and the water filter mayinclude a common ultra-violet radiation lamp mounted in proximity to soas to cooperate with both the primary airflow path and the moisturecollector.

In upstream-to-downstream order, the first refrigeration unit may beadjacent the heat exchanger, the heat exchanger may be adjacent theplenum, the plenum may be adjacent the refrigerant condenser, and therefrigerant condenser may be adjacent the airflow prime mover. Theseelements may be inter-leaved in closely adjacent array.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is, in perspective view, one embodiment of the water condenseraccording to the present invention.

FIG. 2 is a sectional view along line 2-2 in FIG. 1.

FIG. 2 a is an enlarged view of a portion of FIG. 2.

FIG. 2 b is a sectional view along line 2 b-2 b in FIG. 2.

FIG. 3 is a sectional view along line 3-3 in FIG. 1.

FIG. 3 a is an enlarged view of a portion of FIG. 3.

FIG. 3 b is an enlarged view of a portion of FIG. 3 a.

FIG. 3 c is, in perspective view, the internal air conduits of theupstream side of manifold of the water condenser of FIG. 1.

FIG. 4 is a sectional view along line 4-4 in FIG. 1.

FIG. 5 is the view of FIG. 3 in an alternative embodiment wherein theairflow manifold feeding the refrigerant condenser is partitionedbetween the primary and auxiliary airflows.

FIG. 6 is a diagrammatic view of the pre-cooling and condenser cycle andclosed loop refrigerant circuit according to the embodiment of FIG. 1.

FIG. 6 a is the view of FIG. 6 showing an air-to-water heat exchangerdownstream of the air-to-air heat exchanger.

FIG. 6 b is the view of FIG. 6 showing an air-to-water heat exchangerupstream of the air-to-air heat exchanger.

FIG. 7 is, in partially cut away front right side perspective view, analternative embodiment of the present invention wherein two separatefans draw the primary and auxiliary airflows through the evaporator andcondenser respectively.

FIG. 8 is, in partially cut away front left side perspective view, theembodiment of FIG. 7.

FIG. 9 is, in partially cut away rear perspective view, the embodimentof FIG. 7.

FIG. 10 is a partially cut away rear perspective view of the embodimentof FIG. 9.

FIG. 10 a is a sectional view along line 10 a-10 a in FIG. 10.

FIG. 11 is, in partially cut away perspective view a further alternativeembodiment of the present invention wherein the primary airflow passesthrough an air-to-water heat exchanger.

FIG. 12 is a graph of Temperature vs. Time showing the interrelation ofEvaporator Temperature, Processed Air Temperature, Relative Humidity(RH)%, Dew Point Temperature, and Environmental Temperature in thedevice of FIG. 1.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Applicant's U.S. provisional patent application No. 60/632,077 isincorporated herein by reference to the extent that it does not conflictwith this disclosure.

With reference to the drawings wherein similar characters of referencedenote corresponding parts in each view, in one preferred embodiment ofthe present invention, a fan 12 draws a primary airflow along anupstream flow path A through an upstream refrigerant evaporator 14,through an air-to-air heat exchanger 16, and in an alternativeembodiment also through an air-to-water heat exchanger using cold watercollected as condensate from evaporator 14 (better described below),cooperating with an air intake 18 of upstream flow path A, then througha manifold 20 where ambient air is drawn in as auxiliary airflow indirection B through auxiliary air intake 22. The primary airflow entersmanifold 20 in direction C upon leaving heat exchanger 16. The primaryand auxiliary airflows, in the embodiment of FIG. 3, mix in manifold 20then flow in direction D through a downstream refrigerant condenser 24and finally flow through fan 12 so as to be exhausted and heated exhaustin direction E.

The primary airflow is pre-cooled in the air-to-air heat exchanger, andalso in the air-to-water heat exchanger in the alternative embodiment.Humidity in the ambient air drawn in as the primary airflow throughintake 18 is condensed in refrigerant evaporator 14. Water dropletswhich condense are gravity fed in direction F into a collection plate,pan or trough 26 for outflow through spout 26 a. The addition of ambientair drawn in as the auxiliary airflow in direction B into manifold 20provides the higher volumetric airflow rate needed to efficientlyoperate refrigerant condenser 24.

In operation, the primary airflow is drawn in through the upstream airintake 18 of evaporator 14 in direction A and passes between the hollowair-to-air heat exchanger plates 30. Depending on the embodiment of thepresent invention, an air-to-water heat exchanger 90 may cooperate withair-to-air heat exchanger 16 and there may be one, two, three or moreplates 30 in heat exchanger 16. Plates 30 are preferably parallel andare spaced apart to form flow channels therebetween, and between theoutermost plates 30 a and the walls 32 a of the housing 32 of the heatexchanger. Within evaporator 14, in the two evaporator plate embodimentsillustrated, plates 34 are refrigerated by the evaporation ofrefrigerant flowing into cooling coils 34 a. Plates 34 are optimallycooled to a temperature which will cool the primary airflow to justbelow its dew point such as seen plotted from experimental data in FIG.12 so as to condense water vapour in the primary airflow onto thesurfaces of the plates and coils without causing the water vapour toform ice. For example, the primary airflow exiting evaporator 14 indirection H, so as to enter heat exchanger 16, may be cooled to 40°Fahrenheit.

Once the primary airflow has passed between plates 30, and betweenplates 30 a and the walls 32 a of housing 32 (collectively, genericallythe pre-refrigeration set of air conduits), the primary airflow isturned one hundred eighty degrees in direction I by and within an endcap manifold 36 which extends the length of the upper ends of plates 30.

Plates 30 themselves are rigidly supported in parallel spaced apartarray sandwiched by and between planar end plates 38. The end plateshave an array of apertures 38 a therethrough. The apertures align withthe open ends of sealed conduits 30 b through the plates, as best seenin FIGS. 3, 3 a and 3 b, so that, once the airflow has turned onehundred eighty degrees in direction H through upstream side manifold 40,the airflow then passes in direction J through apertures 38 a and alongthe length, of conduits 30 b (the post-refrigeration set of airconduits) so as to exit from the corresponding apertures 38 a downstreamin the opposite end plate 38′. In particular, side manifold 40 in theillustrated embodiment of FIG. 3 c, which is not intended to belimiting, segregates airflow in direction H into three flows H₁, H₂ andH₃ so as to enter into corresponding conduits 30 b, themselves arrangedin three banks 30 b ₁, 30 b ₂ and 30 b ₃ arranged vertically one on topof the other as seen in FIG. 2. Fences 40 b divide airflows H₁, H₂ andH₃ from one another and align the airflows with their corresponding bankof sealed conduits 30 b, so that airflows H₁, H₂ and H₃ are aligned forflow into, respectively, conduit banks 30 b ₁, 30 b ₂ and 30 b ₃. Fences40 b also align with plates 34 so as to partially segregate the infeedto airflows H₁, H₂ and H₃ to come from, respectively, between theoutside plate 34 and the outside wall 14 a, between the inside andoutside plates 34, and between the inside plate 34 and the inside wall14 b. A lower cap 40 a seals the end of pan 26 and channels moisturecollected from side manifold 40 into pan 26, better seen in FIG. 2 b.Air-to-air heat transfer in direction K occurs through the solid wallsof plates 30 so that the primary airflow in conduits 30 b cools theprimary airflow between the plates.

Upon leaving the apertures 38 a′ in end plates 38′, the airflow is againturned approximately one hundred eighty degrees in direction C by andwithin downstream side manifold 42 which extends the height of end plate38′. Side manifold 42 directs airflow into manifold 20 through a port 44leading into the upstream end of manifold 20. An ambient air intake 22feeds ambient air in direction B into manifold 20 so as to, in onecombined airflow embodiment, mix with the airflow from heat exchanger 16with ambient air from auxiliary air intake 22. The flow rate of theauxiliary airflow through intake 22 is selectively regulated byactuation of damper 20 a (shown in FIG. 3 in its closed position indotted outline and in its open position in solid outline). The mixedairflow is then drawn in direction D into refrigerant condenser 24 so asto pass between the louvers 24 a or coils or the like. Condenser 24condenses refrigerant flowing in lines 46 a (illustrateddiagrammatically in dotted outline in FIG. 4) once compressed bycompressor 46. The combined airflow then enters the in-line fan 12 andexhausts from the fan in direction E.

Atmospheric air enters intake 18 in direction A through screen 50,passing through pre-filter 52, then through a high quality filter, suchas HEPA filter 54. Air flow leaving condenser 24 may pass throughanother filter 56. Filter 56 inhibits contaminates from entering the fanand thus keeps contaminants from getting into evaporator 14. Once theprimary airflow has been processed through the two cooling stages of,respectively, heat exchanger 16 and refrigerant evaporator 14, theprimary airflow may not be sufficiently cool to assist in therefrigerant cooling in refrigerant condenser 24. Thus the primaryairflow may be exhausted entirely from the system without flowingthrough condenser 24 without significantly affecting performance orwhere the primary airflow is somewhat cool, it may be used to assist incooling condenser 24. If the air that has passed through the evaporator14 and heat exchanger 16 is exhausted upstream of condenser 24, thecondenser 24 will draw its own air stream, that is the auxiliaryairflow, directly from the ambient air outside the system. The use ofthe two air streams, primary and auxiliary has advantages in allowing asignificant increase in airflow through the condenser versus theevaporator.

A controller 48 may do multiple tasks and the system may requiremultiple controllers if it is not beneficial or practical to build themall into the same unit. The controller 48 may be designed to accommodatea varying power input such as would be the case if the unit was hookedup directly to a photovoltaic panel. Controller 48 may also ensure thatthe refrigeration system pressures are maintained.

There are two pressures involved in a refrigeration system such as isemployed in this design. These are the suction pressure (low side) andthe discharge pressure (high side). For optimal performance the low sideor suction pressure may be approximately 30 psi. The high side ordischarge pressure is much harder to control and may be within the 120psi to 200 psi range for optimal performance. With a normalrefrigeration system the high side pressure is much easier to controlusing conventional refrigeration controls, and poses little concern.With a system such as this, that is under constant changing load withlarge fluctuations in both temperature and humidity, the pressures areprone to change and can quickly move outside of the optimal range. Thiscan cause damage to the system as if the discharge pressure gets to high(over 250 psi) it may be very hard on the system and can cause internaldamage to the valves in the compressor, the insulation on the electricalwiring, and may even cause the formation of waxes, as well as decreasingthe overall efficiency of the system. These pressures may be controlledto some degree by controlling the pressures within the system andthrough controlling the flow of refrigerant. The high side or dischargemay be controlled by regulating the quantity and temperature of the airthat passes through the condenser. If the discharge pressure is too low(below 120 psi) the cooling system becomes compromised and functionsbelow its capability. In this case the controller is designed to turnthe fan off and allow the pressure to rise. If the pressure gets toohigh the controller will turn the fan on and the pressure will drop.This is a simple and inexpensive way to control the system dischargepressure.

Controller 48 may also find the optimal airflow rate through thecondenser so as to moderate the discharge (also called backpressure) toan acceptable range (150 psi may be optimal). In this design the fan iskept at the optimal speed rather than turning off and on, so as toensure proper system pressures and optimal operation of therefrigeration system.

In ensuring that an ideal operation of the device is maintained,different systems may be employed. They are as follows.

The ideal location within the system will be determined for where theinternal airflow should be reaching its dew point. This location mightbe between the heat exchanger and the evaporator plates (first pass). Acontroller with sensors monitors environmental conditions and calculatesinternally what the dew point is. Sensors are placed within the systemsuch as mentioned above, that allow the controller to monitor thesensors, thereby determining where the temperature is with respect todew point. Thus, if optimal system function is to create dew point atthis sensor the controller will slow down or speed up the fan in acontinual effort to optimize the system. In another embodiment apressure differential gauge may be used to offer feedback to thecontroller assisting in its function to optimize the airflow. Thepresent system is designed to keep the airflow just below dew point andto track, dew point continuously as conditions change. As seen in thetest data set of FIG. 12, the dew point is continuously tracked by theprocessed air temperature ensuring optimal operation.

In an alternative embodiment as seen in FIGS. 7-10 and 10 a the primaryand auxiliary airflows are entirely separate. Whereas in the previouslydescribe embodiment, the primary airflow after passing through theair-to-air heat exchanger wherein the lowered temperature of the primaryairflow leaving the refrigerant evaporator is used to pre-cool theincoming primary airflow rather than be wasted, and the primary airflowthen flowing into the manifold wherein it is mixed with the auxiliaryairflow so as to provide the increased mass flow volume for therefrigerant condenser, in this embodiment, control of the primaryairflow is provided by a separate fan for increased accuracy of controlof the primary airflow through the two cooling stages namely the heatexchanger and refrigerant evaporator.

Thus as may be seen in the illustrations, fan 60 draws auxiliary airflowthrough refrigerant condenser 62 in direction M via intake 64. Asbefore, the refrigerant condenser is in the same refrigeration circuitas the refrigerant evaporator, that is, is in the same refrigerationcircuit as the second cooling stage. As before, an air-to-air heatexchanger provides the first cooling stage. Thus the primary airflow, asbefore, enters the heat exchanger prior to entry into the refrigerantevaporator. In particular, primary airflow enters air-to-air heatexchanger 66 in direction N through a lower intake 68 having passedthrough air filters as previously described (not shown). The primaryairflow passes through hollow conduits 66 a across the width of the heatexchanger, exiting conduit 66 a in direction P so as to be turned onehundred eighty degrees in end manifold 70. The primary airflow thenflows between refrigerant evaporator plates 72 in direction Q whereinthe primary airflow is cooled below it's dew point without freezing.Moisture thus condenses out of the primary airflow onto plates 72 and isharvested through a spout 74 into a collection pan or the like (notshown).

The primary airflow exits from the refrigerant evaporator through slot76 and travels in direction R downwards between conduits 66 a so as toexit heat exchanger 66 in direction S through slot 78. The primaryairflow is then drawn through fan housing 80 and fan 82 so as to exit asexhaust from fan 82 in direction T.

The de-linking of the primary and auxiliary airflows so as to requireseparate fans, respectively fans 82 and 60, provide for condenser 62functioning at a greater capacity without affecting optimization of thebalance of the cooling between the first and second cooling stages of,respectively, the heat exchanger 66 and the evaporator plates 72. Thusthe lower volume fan 82 may be controlled by a processor (not shown) todetermine the current environmental conditions affecting optimization ofcooling and condensation for example by varying the power supplied tofan 82 to thereby control the velocity and mass flow rate of the primaryairflow through the two cooling stages. Thus the primary airflow may bedrawn through the cooling stages at a velocity which is not so high asto affect the maximum condensation of moisture, and not too low so as towaste energy in cooling the primary airflow too far below the dew point.Thus by monitoring environmental conditions, for example the humidityand temperature, the fan speed of fan 82 may be selectively controlledto optimize production of condensation regardless of ambientenvironmental conditions. Thus in a very humid environment, fan 82 willbe powered to draw a higher mass flow rate of the primary airflowthrough the two cooling stages, whereas in lower humidity conditions theprimary airflow will require more time to optimize the condensation andthus slower fan speeds may be used to provide for optimized condensateproduction.

In the further embodiment of FIG. 5 a partition 100 partitions manifold20 so that the primary and secondary airflows do not mix. For example,partition 100 may bisect the intake into refrigerant condenser 24.Otherwise, partition 100 may be mounted relative to the intake intorefrigerant condenser 24 so as to provided for a greater volume ofauxiliary airflow in direction D′ flowing through condenser 24. The airspeed velocity and mass flow rate of the primary airflow through the twocooling stages of the heat exchanger and refrigerant evaporatorrespectively, may be, for example, controlled by selectively positioningthe position of partition 100 relative to condenser 24 or otherwise by,in conjunction with, the use of airflow dampers or other selectivelycontrollable airflow valves.

The appropriate processing of ambient air provides for optimal operationof the condenser unit. While conventional condensers may simply drivehigh volumes of air through a cooling system (typically just anevaporator without a heat exchanger), these systems have notaccommodated a system designed for power efficiency as is in the presentinvention which employs techniques to extract the maximum quantity ofwater with the least power requirements. This may be accomplished in anumber of ways, as follows.

Environmental conditions are monitored by the system and at anappropriate point in the system, such as between the heat exchanger andthe evaporator (first pass) the temperature relative to dew point ismonitored. If the air at this point is too far above dew point the fanthat draws air through this section of the unit may decrease its speedthus slowing the air and allowing more time for the air to cool prior toreaching the evaporator plates. If the air at this point is below dewpoint then the system may increase the fan speed and continue tooptimize the airflow stream. Other conditions throughout the device maybe monitored as well and this information may be used by controller 48to further tune the device. Humidity levels leaving the system may beused as a means to determine exactly how much water has been extractedfrom the air and with this information, the system may modify itsconfiguration thus ensuring optimal performance.

In the alternative embodiment of FIGS. 6 b, 11 and 11 a, air-to-waterheat exchanger 90 is mounted upstream of the air-to-air heat exchangeralong the primary airflow. Water collected in moisture collector 26 isdirected for example by conduit 26 a into water reservoir 90 a fromwhich the water may be collected for end use. The water in reservoir 90a is chilled, having just been condensed into and recovered from theevaporate plates. Thus the primary airflow passing through air conduits90 b in direction A′ is cooled by the water cooling the conduits 90 bbefore the primary airflow enters the air-to-air heat exchanger forfurther pre-cooling as described above. This further improves theefficiency of the condenser as it takes advantage of the coldtemperature of the collected water.

In one embodiment, various parts and components of the unit may beeither constructed with Titanium Dioxide or my simply be coated withTitanium Dioxide. Using this material to construct various parts for thedevice, or using this material as a coating on these parts, will ensurethat these components are kept clean and free of contaminates and thatthe water source created by the device is kept free of unwantedcontaminates. Virtually any of the internal components may be made ofthis inexpensive and abundant material. In addition, either all thematerial that composes the storage container or just the inner liningmay be made of this material as a means to ensure that that water sourceis kept clean and free of unwanted contaminates.

This material may be used as an antimicrobial coating as thePhotocatalytic activity of titania results in a thin coating of thematerial exhibiting self cleaning and disinfecting properties underexposure to ultra-violet (UV) radiation. These properties make thematerial ideal for application in the construction of our watercondensation system helping to keep air and water sources clean and freeof contaminates while as well offering the benefits of self repairshould a surface be scratched or compromised.

Titanium dioxide, also known as titania, is the naturally occurringoxide of titanium, chemical formula TiO2. Approved by the food testinglaboratory of the United States Food and Drug Administration (FDA),Titanium Dioxide is considered a safe substance and harmless to humans.

Scientific studies on photocatalysis have proven this unique butabundant substance to be anti-bacterial, anti-viral and fungicidalmaking it ideal for self cleaning surfaces and may be used fordeodorizing, air purification, water treatment, and water purification.

As Titanium dioxide is a semiconductor and is chemically activated bylight energy, appropriate lighting sources may be added at variousstrategic points throughout the device to ensure that the air and watersources are kept clean and free of unwanted substances. Some of the mostbeneficial places throughout the system that might use this TiO2 exposedto UV radiation are the heat exchanger, evaporator plates, and thestorage container, however virtually all surfaces that come in contactwith either the air or the water source may be constructed with TitaniumDioxide. One strategic place for the lighting source might be betweenthe heat exchanger and the evaporator plates using reflective materialto ensure that the light radiates through both theses sections of thedevice made, or coated with TiO2.

As a pure titanium dioxide coating is relatively clear, this substancemay be used for the inner lining of tubing that carries the water fromthe evaporator plates to the storage container and may become part ofthe UV purification system. This material has an extremely high index ofrefraction with an optical dispersion higher than diamond so in order toenhance its desired effects, coiled tubing that surrounds the lightsource, may be encased in a reflective material so as to ensure thatlight is given an adequate opportunity to come in contact with thesurface of the material and thus create the desired effect.

In applications where this UV and Titanium purification system is usedinside of a storage container of some sort, an opening may be situatedat the bottom of the reflective encasement such that light will escapeto offer these same desire effects to occur within the storagecontainer. Alternatively, a separate light may be used within thestorage container assuming it is not practical for various applicationsto use only one light to serve this purpose.

As will be apparent to those skilled in the art in the light of theforegoing disclosure, many alterations and modifications are possible inthe practice of this invention without departing from the spirit orscope thereof. Accordingly, the scope of the invention is to beconstrued in accordance with the substance defined by the followingclaims.

1. A water condenser comprising: a housing having a first air intake forentry of a first airflow, said first air intake mounted to an air-to-airheat exchanger having a pre-refrigeration set of air conduitscooperating in fluid communication with said first air intake; forintake of said first airflow into said pre-refrigeration set of airconduits, said heat exchanger having a post-refrigeration set of airconduits arranged relative to the pre-refrigeration set of air conduitsfor beat transfer between said pre-refrigeration set of air conduits andsaid post-refrigeration set of air conduits, a refrigeration unitcooperating with said pre-refrigeration set of air conduits for passageof said first airflow from a downstream end of the pre-refrigeration setof air conduits into an upstream end of said refrigeration unit, whereinsaid refrigeration unit includes refrigerated surfaces over which saidfirst airflow passes as it flows from said upstream end of therefrigeration unit to a downstream end of said refrigeration unit, saidfirst airflow cooled in said refrigeration unit below a dew point ofsaid first airflow so as to condense moisture from said first airflowonto said refrigerated surfaces for gravity-assisted collection of thefirst moisture into a moisture collector mounted under saidrefrigeration unit, an air-to-water heat exchanger cooperating with saidair-to-air heat exchanger for cooling said first airflow wherein saidfirst airflow is passed through said air-to-water heat exchanger andsaid first moisture from said moisture collector is simultaneouslypassed through said air-to-water heat exchanger so that said firstmoisture, cools said first airflow, said downstream end of saidrefrigeration unit cooperating with, for passage of said first airflowinto, an upstream end of said post-refrigeration set of air conduits,said first airflow exhausting from a downstream end of saidpost-refrigeration set of air conduits, wherein said first airflow insaid post-refrigeration set of air conduits pre-cools said first airflowin said pre-refrigeration set of air conduits, control means forcontrolling the temperature of said first airflow in saidpre-refrigeration set of air conduits so that it remains above a dewpoint temperature of said first airflow when in said pre-refrigerationset of air conduits and for controlling the temperature of said firstairflow in said refrigeration unit so that it drops below a dew pointtemperature of said first airflow when in said refrigeration unitwithout freezing, an airflow mover urging said first airflow into saidfirst air intake, along said pre-refrigeration set of air conduits,through said refrigeration unit, and along said post-refrigeration setof air conduits.
 2. The device of claim 1 further comprising an airplenum having upstream and downstream ends, said upstream end of saidair plenum cooperating with said downstream end of saidpost-refrigeration set of air conduits so that said first airflow flowsinto said air plenum at said upstream end of said plenum, said plenumhaving an auxiliary air intake into said plenum, for intake of anambient second airflow into said plenum, said downstream end of saidplenum cooperating in fluid communication with a refrigerant condenserin a refrigeration circuit including said first and second airflowsexhausting from a downstream end of said refrigerant condenser, whereinsaid airflow mover urges said first and second airflows through saidplenum and said refrigerant condenser.
 3. The device of claim 1 whereinsaid refrigeration unit is a refrigerant evaporator.
 4. The device ofclaim 2 further comprising a selectively actuable airflow metering valvemounted in cooperation with said auxiliary air intake for selectivelycontrolling the volume and flow rate of said second airflow passing intosaid plenum.
 5. The device of claim 4 further comprising an automatedactuator cooperating with said metering valve for automated actuation ofsaid metering valve between open and closed positions of said valveaccording to at least one environmental condition indicative of moisturecontent in said first airflow.
 6. The device of claim 5 wherein saidautomated actuator is a bi-metal actuator and wherein said at least oneenvironmental condition includes ambient air temperature external tosaid housing.
 7. The device of claim 5 wherein said automated actuatorincludes a processor cooperating with at least one sensor, said at leastone sensor for sensing said at least one environmental condition andcommunicating environmental data corresponding to said at least oneenvironmental condition from said at least one sensor to said processor.8. The device of claim 3 further comprising a processor cooperating withat least one sensor, said at least one sensor for sensing said at leastone environmental condition and communicating environmental datacorresponding to said at least one environmental condition from said atleast one sensor to said processor, wherein at least one environmentalcondition of said at least one environmental condition is chosen fromthe group consisting of: ambient air temperature, first airflowtemperature of said first airflow, humidity, barometric air pressure,air density, airflow velocity, air mass flow rate, temperature of saidrefrigerated surface.
 9. The device of claim 8 wherein said at least onesensor senses said at least one environmental condition in or inproximity to said first airflow.
 10. The device of claim 9 wherein saidfirst airflow temperature environmental condition includes airtemperatures in said pre-refrigeration and post-refrigeration sets ofair conduits.
 11. The device of claim 9 wherein said first airflowtemperature environmental condition includes air temperature in saidrefrigeration unit.
 12. The device of claim 11 wherein said at least onesensor senses said at least one environmental condition in said heatexchanger, and wherein said processor regulates said first airflow insaid first refrigeration unit so that said air temperature in saidrefrigeration unit is below said dew point of said first airflow, butabove freezing.
 13. The device of claim 11 wherein said processorcalculates said dew point for said first airflow based on said at leastone environmental condition sensed by said at least one sensor.
 14. Thedevice of claim 11 wherein said airflow mover is selectivelycontrollable and wherein said processor regulates said first airflow soas to minimize said air temperature of said first airflow from droppingbelow said dew point for said first airflow while in said heat exchangerto minimize condensation within said heat exchanger.
 15. The device ofclaim 9 wherein said airflow mover is at least one fan in a flow pathcontaining said first airflow.
 16. The device of claim 15 wherein saidat least one fan includes a fan downstream of said heat exchanger. 17.The device of claim 15 further comprising at least one air filter insaid flow path.
 18. The device of claim 17 further comprising a waterfilter for filtering water harvested from said refrigeration unit. 19.The device of claim 17 wherein said at least one air filter includes anultra-violet radiation lamp mounted in proximity to so as to cooperatewith said flow path.
 20. The device of claim 17 wherein said waterfilter includes an ultra-violet radiation lamp mounted in proximity toso as to cooperate with said moisture collector.
 21. The device of claim17 wherein said at least one air filter and said water filter include acommon ultra-violet radiation lamp mounted in proximity to so as tocooperate with said flow path and said moisture collector.
 22. Thedevice of claim 1 wherein said refrigeration unit includes a platecondenser having at least one plate.
 23. The device of claim 22 whereinsaid at least one plate is a plurality of plates.
 24. The device ofclaim 23 wherein said plurality of plates are mounted in substantiallyparallel spaced apart array.
 25. The device of claim 2 where, inupstream-to-downstream order, said refrigeration unit is adjacent saidheat exchanger, said heat exchanger is adjacent said plenum, said plenumis adjacent said refrigerant condenser, and said refrigerant condenseris adjacent said airflow mover.
 26. The device of claim 25 wherein saidrefrigeration unit, said heat exchanger, said plenum, said refrigerantcondenser, and said airflow mover elements are inter-leaved in closelyadjacent array.
 27. The device of claim 2 wherein said first airflow hasa corresponding first mass flow rate, and wherein said second airflowhas a corresponding second mass flow rate, and wherein a combinedairflow of said first and second airflows is the sum of correspondingfirst and second mass flow rates so that a combined mass flow rate ofsaid combined airflow is greater than said first mass flow rate.
 28. Thedevice of claim 1 wherein said air-to-water heat exchanger is upstreamof said air-to-air heat exchanger along said first airflow.
 29. Thedevice of claim 1 wherein said air-water heat exchanger is downstream ofsaid air-to-air heat exchanger along said first airflow.
 30. The deviceof claim 1 wherein elements including said housing, said first airintake, said air-to-air heat exchanger, said sets of air conduits, saidrefrigeration unit, said moisture collector, said air-to-water heatexchanger, moisture conduits, or said airflow mover include titaniumdioxide as a constituent component.
 31. The device of claim 30 whereinsaid titanium dioxide is a coating on at least internal surfaces of saidelements.
 32. The device of claim 30 further comprising at least onesource of radiation is mounted within said housing so as to irradiateinternal surfaces of at least one of said elements.
 33. The device ofclaim 32 wherein said at least one source of radiation is a source ofultra-violet radiation.
 34. The device of claim 32 wherein said sourceof radiation is mounted between said heat exchanger and said evaporator.35. The device of claim 34 further comprising a reflector mountedadjacent said source of radiation to reflect radiation onto internalsurfaces of said heat exchanger and said evaporator.